Energy Sublevels
Single lines were made up of many lines close together
Multiple lines close together could not have resulted from electrons dropping to two different energy levels → lines were too close together
It was proposed that each main energy level (except the first) were made out of a number of sublevels that were close in energy
Number of sublevels was equal to the value of n
Example:
n=2 → 2 sublevels
n=3 → 3 sublevels